no he is not he can be killed again but as for bring eternal we are not sure yet because we have not been given much info on that.
How can brook die, he has no organs to get pierced in a fight, and he doesn't bleed, though he did express pain when fighting ryuma. I think theres still more to Brooks Df power since it really hasn't been explained by oda yet, brook thinks he can only come back once but that might not be the case.
plus he had to be saved from the water in the past meaning it can probably kill him. also, lol whether some one can come back or not getting crushed in to dust will kill you LOL. brook said he gets an extra life. there is no reason to believe that he can come back more than once.
there might be other powers to his DF but no reason to believe that that is one of them
To believe or to not believe that is not the question, the question isthere might be other powers to his DF but no reason to believe that that is one of them
Have you ever eaten an mclobster?
+ sounds like there's room for leeway. It's also possible, judging by his crazy youthful ability @ the approximate age of 90yrs old that the fruit not only starts you life again but starts you with the youth of a baby. Not saying those things can't kill him(btw forgot acid), but it's also possible he can't die of old age, and the others died in battle, and or 1 of the methods you mentioned earlier, thus why this secret was never discovered.
(Feel like I had this conversation before....
In buggy's crew should only be lvl 1-4 guys, since they never went back to 5(freezing hell) , if I remember correctly they just went from level 6 to level 4 (where they freed daz bones and the other level 4's) then made a run for it.. it would still make buggy's crew strong, but not like WB pirates strong ... if a bunch of lvl 6 pirates joined Buggy he would auto become a world contender.
or am I remembering something wrong?
iva let loose level 5 guys and they ended up with buggy to along with the 1-4 guys that were strong enough to make it out. and some level 6 guys made it out but some of them did not go with BB. only some of them did. there are an unknown number of level 6 guys that made it out. but that was after luffy and his group left I.D. so there are no level 6 guys with buggy but there are more level 6 guys out there than the ones with buggy.